/Engine/Source/Runtime/GeometryCore/Public/TriangleTypes.h
true if QueryPoint is inside triangle
static bool IsInside ( const [TVector2](API\Runtime\Core\Math\TVector2)< RealType > & A, const [TVector2](API\Runtime\Core\Math\TVector2)< RealType > & B, const [TVector2](API\Runtime\Core\Math\TVector2)< RealType > & C, const [TVector2](API\Runtime\Core\Math\TVector2)< RealType > & QueryPoint )